We want this on musl too.

--- a/librhash/byte_order.h
+++ b/librhash/byte_order.h
@@ -4,7 +4,7 @@
 #include "ustd.h"
 #include <stdlib.h>
 
-#if defined(__GLIBC__)
+#if defined(__linux__)
 # include <endian.h>
 #endif
 #if defined(__FreeBSD__) || defined(__DragonFly__) || defined(__APPLE__)
